States of Consciousness

States of consciousness are the distinct awarenesses one has of the environment and oneself. These include deep sleep, light sleep, relaxation, meditation and alert awareness. In yoga or meditation practice, yogis may be able to alter their state of consciousness. The term, altered state of consciousness, is generally defined as "any state of awareness which is different from the normal waking consciousness."

Switching between different states of consciousness has been found to be associated with switching to a different pattern of brain waves. These can be measured scientifically using an electroencephalograph to detect electrical activity in the brain.

Yogapedia explains States of Consciousness

Different states of consciousness are connected with different levels of focus and even increased creativity. They may be induced through meditation, yoga practice or through pharmacological substances. They may also occur unintentionally, through accidents, trauma or medical conditions such as epilepsy.

There are four main types of brain waves which are associated with different states of consciousness: alpha (deep relaxation or meditation), beta (alert awareness), theta (light sleep) and delta (deep sleep).

In yoga, practices such as yoga nidra aim to shift the state of consciousness to a state which is deeply relaxed and meditative, yet awake. As such, the yogi will have a heightened awareness of their inner world.